Astronomy:Omicron Gruis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Grus |
| Right ascension | 23h 26m 36.57748s[1] |
| Declination | −52° 43′ 17.7656″[1] |
| Apparent magnitude (V) | 5.52[2] |
| Characteristics | |
| Spectral type | F4 V[3] + M3/M4[4] |
| B−V color index | +0.40[2] |
| Variable type | δ Sct[5] |
| Astrometry | |
| Proper motion (μ) | RA: +34.52[1] mas/yr Dec.: +130.66[1] mas/yr |
| Parallax (π) | 32.50 ± 0.37[1] mas |
| Distance | 100 ± 1 ly (30.8 ± 0.4 pc) |
| Absolute magnitude (MV) | 3.01[6] |
| Details | |
| ο Gru A | |
| Mass | 1.31[7] M☉ |
| Surface gravity (log g) | 4.19[7] cgs |
| Temperature | 6,763±230[7] K |
| Metallicity [Fe/H] | –0.10[3] dex |
| Rotational velocity (v sin i) | 20.4±0.3[6] km/s |
| Age | 1.026[7] Gyr |
| ο Gru B | |
| Mass | 0.3[4] M☉ |
| Age | 1.1[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
ο Gruis, Latinised as Omicron Gruis, is a binary or triple star[4] system in the southern constellation of Grus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.52.[2] Based upon an annual parallax shift of 32.50 mas as seen from the Earth,[1] the system is located 100 light years from the Sun.
The pair form a close spectroscopic binary system with a physical separation of about 14.9 astronomical units.[4] The primary component is an F-type main sequence star with a stellar classification of F4 V,[3] a star that is currently fusing its core hydrogen. It is a probable delta scuti variable showing periodicities of 4.7 and 5.5 cycles per day with amplitudes of 0.014 and 0.011 magnitudes, respectively.[5] The secondary companion is a red dwarf with a mass of about 0.3 solar, suggesting a class of M3/M4.[4] Ehrenreich et al. (2010) noted the detection of a tertiary companion that is not causing the detected radial velocity shifts which would make this a triple star system.[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 Lake, R. (1965), "Photometric Magnitudes and Colours for Bright Southern Stars (Sixth List)", Monthly Notes of the Astronomical Society of Southern Africa 24: 41, Bibcode: 1965MNSSA..24...41L.
- ↑ 3.0 3.1 3.2 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Ehrenreich, D. et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics 523: A73, doi:10.1051/0004-6361/201014763, Bibcode: 2010A&A...523A..73E.
- ↑ 5.0 5.1 Lampens, P. et al. (April 2000), "delta Scuti stars in stellar systems: On the variability of HD 220392 and HD 220391", Astronomy and Astrophysics 356: 895–902, Bibcode: 2000A&A...356..895L.
- ↑ 6.0 6.1 Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics 542: A116, doi:10.1051/0004-6361/201118724, Bibcode: 2012A&A...542A.116A.
- ↑ 7.0 7.1 7.2 7.3 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ "pi.02 Gru". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=pi.02+Gru.
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